The Sudarshana lake (reservoir) in Saurashtra, later repaired by the Shaka ruler Rudradaman, was originally built during the rule of the:

The Sudarshana lake, an artificial reservoir in Saurashtra (western India), was originally built during the rule of the Mauryas.

History of the Sudarshana lake:

• It was built by Pushyagupta, a provincial governor (rashtriya) of Chandragupta Maurya, by damming streams in the region.
• During Ashoka's reign, his governor Tushaspha (a Yavana, possibly of Greek or Persian origin) added canals (conduits) to it.
• In about 150 CE, a great storm and floods broke the dam.
• The Shaka (Western Kshatrapa) ruler Rudradaman I repaired it at his own expense, without imposing forced labour or extra taxes on the people.
• In the 5th century CE, during the reign of the Gupta emperor Skandagupta, the dam broke again and was repaired by the governor Parnadatta and his son Chakrapalita.

Sources:

• Rudradaman's inscription, written in about 150 CE, describes the history of the lake and its repair.
• It is one of the earliest long inscriptions in Sanskrit, and is admired for its literary style.
• It also describes Rudradaman's victories, including over the Satavahana ruler, and his knowledge of grammar, music and logic.
• Skandagupta's inscription records the later repair.

Importance:

• The history of the lake shows that the Mauryas and later rulers took an interest in irrigation and public works.
• It shows the continuity of administration over many centuries.
• NCERT mentions the Sudarshana lake as an example of irrigation works built by rulers.

Mauryan public works:

• The Arthashastra mentions irrigation and the collection of water taxes.
• Megasthenes mentions officers who supervised rivers and measured land, and inspected sluices.

Why not the other options?

• ✗The Guptas repaired the lake later, but did not build it.
• ✗The Satavahanas ruled the Deccan.
• ✗The Kushanas ruled the north-west and north India.